Process and device for producing fancy ply yarns with high efficiency uptwisters

ABSTRACT

Fancy yarns are produced by twisting a core yarn in one direction, and then winding an effect yarn in the opposite direction about the core yarn while simultaneously varying the velocity of the core yarn so as to group the turns of effect yarn on the core yarn. A plurality of oppositely wound effect yarns can be applied. The direction of twist of each yarn remains unchanged throughout.

v United States Patent [191 1111 3,780,512

Ratti Dec. 25, 1973 [54] PROCESS AND DEVICE FOR PRODUCING 3,367,097 2/1968 Menasoff 57/34 AT FANCY Y YARNS WITH HIGH 3,507,108 3/1970 Yoshimura et al. 57/91 X I 3,166,885 1/1965 Bridgeman et al 57/17 X EFFlCIENCY UPTWSTERS 3,053,040 9/1962 Livingston 57/160 X [76] Inventor: Michele Ratti, via Fascara 5, Luino, 2,847,703 8/1958 Schrenk et al. 57/91 UX Italy v [22] Filed: Jan. 26, '1972 Primary ExaminerDonald E. Watkins 1 pp No 1 Attorney-Irvin S. Thompson et al.

[30] Foreign Application Priority Data [57] ABSTRACT Feb. 10, 1971 Italy.. 20404/71 Fancy yams are produce-d by twisting a core yam in one direction, and then winding an effect yarn in the (gill. 57/:)6(,)257/3 opposite direction about the core yam while Simulta [58] Fie'ld 6 13 neously varying the velocity of the core yarn so as to 57/14 AT group the turns of effect yarn on the core yarn. A plurality of oppositely wound efiect yarns can be applied. 5 6] Reierences Cited The direction of twist of each yarn remains unchanged throughout. UNITED STATES PATENTS 3,570,233 3 1971 Nalpas et al. 57/16- 5 Claims, 11 Drawing Figures 1 PROCESS AND DEVICE FOR PRODUCING FANCY PLY YARNS WITH HIGH EFFICIENCY UPTWISTERS The present invention pertains to a process and device for producing fancy ply yarns with high efficiency uptwisters having axially bored core spindles, which ing thus avoiding the successive heat fixation treatment (steaming) and also allowing a production rate greater than that of the ring twister under similar conditions.

According to the process at least two of the yarns making up the ply yarn are twisted in opposite directions and at least one of the yarns making up the ply yarn is subjected during the twisting process to a variable winding-off speed.

The device which carries out the above said process is characterized by a plurality of bobbins or axially bored spindles each suited to provide a thread forming the ply yarn and by an optional fixed bobbin providing the core, said bobbins and spindles being arranged one after the other on the same axis and of which at least two revolve in opposite directions and characterized by at least a mechanism to periodically pull and release the yarnthat must be subjected to a variable windingoff speed.

In the accompanying drawings:

FIG. 1 is a schematic view of a ring twister generally used to obtain fancy ply yarns;

FIG. 2 is a high efficiency uptwister of the normal type with axially bored spindles, which does not allow one to obtain the fancy ply yarn which can be obtained by means of the ring twister shown in FIG. 1;

FIG. 3' is a schematic view of a high efficiency uptwister modified according to thepresent invention, which allows one to obtain the desired fancy ply yarn;

FIG. 4 shows a fragmentary view of the mechanism which during the twisting process imparts a variable winding-off speed to one ofthe threads making up the ply yarn; Y

FIG. 5 is a front view of a portion of the ply yarn obtained by the device of FIG. 3;

FIGS. 6a, 6b and 6c show three further possible shapes of fancy ply yarns which can be obtained by the device shown in FIG. 3;

FIG. 7 is an alternate arrangement for the device of the present invention;

FIGS. 8d and 8e shows two possible shapes of fancy ply yarns which can be obtained by the device of FIG. 7.

It should be clear that the expression fancy ply yarn" indicates a yarn which consists of one or more threads different from each'other in color, kind of each single thread and length of each of said component threads.

By examining for example FIGS. 6a, 6b and 6c and FIGS. 8d and 8e it can be seen how the shown ply yarn gives a quite different visual impression depending either one or more component threads are helically twined with a different pitch around a yarn acting as a central core, and also because said spiraling'presents here and there a number of windings brought close to each other in order to form a kind of knot or knop."

Fancy ply yarns of this type meet with the favour of the public today and it is therefore important to be able to produce them not only by means of the ring twisters schematically shown in FIG. l, as it is presently common in the art, but also preferably by means of the high process prevents the completed ply yarn from untwist- 2 efficiency uptwisters, shown in FIG. 2, not suitable so far for this type of production.

For a fuller understanding of the differences between the operation of the ring twister and the operation of the high efficiency uptwister reference is made to FIG. 1, in which a fancy ply yarn is obtained as follows: from a fixed tapered bobbin the thread 2, which is one of the components of the fancy ply yarn to be manufactured is drawn off by means of the feed rollers 3 and 4 to be delivered through the guide eye 5 to the revolving ring 6 of a spindle 7. Similarly, from the fixed tapered bobbin 8 the thread 9 pulled along by the rollers 10, 11 is also drawn through the guide eye 5 and delivered to the twisting ring 6 of the revolving spindle 7. The ring 6 moves up and down parallel to arrows l2 distributing the ply yarn allover the surface of the rotating spindle By varying the feeding speed of the thread 2 by means of the rollers 3, 4, that is by varying the angular speed of the rollers 3,4, one of the two threads, for example the thread 2, is made to arrive at the ring 6 more slowly or even to stop, while the other thread 9 is delivered to the ring 6 at constant speed.

The result is a fancy ply yarn which can present knots or knops similar but not identical to the ones shown in FIG. 60 depending on the variations of speed of the feed rollers 3,4 which deliver the thread 2.

The ply yarn obtained by the ring twister just described presents a serious disadvantage; the two threads 2 and 9 being twined in the same direction around the revolving spindle 7, when the twisting process is completed and the ply yarn is unwound from the spindle, it tends to distort due to the inner elasticity of its components and mainlybecause the two threads, as mentioned, have been twisted in the same direction. A fabric made of said fancy ply yarn would then present waviness with unpleasant visual impression. In order to avoid said disadvantage the thread wound around the spindle 7 is subjected after the twisting operation to a heat fixation operation, so'called steaming," to fix the component threads in their position finally reached.

' The operation of the high efficiency uptwister shown in FIG. 2 is based on a quite different principle, but it does not allow one to obtain the fancy ply yarn as previously explained in the case of the ring twister.

The above mentioned high efficiency uptwister consists of a bobbin or spindle 13 and of a coaxial bobbin or spindle 14. The thread 15 which unwinds from the lower spindle 13 passes through the hollow axis 16 of the upper spindle l4 and goes to the take-up bobbin 17. If the lower spindle 13 is stationary and the upper spindle l4 revolves in a certain direction, the thread 15 does not twist and act as a core around which the thread 18 helically twines coming from the spindle 14'. If now the lower spindle 13 instead of being stationary revolves in the opposite direction of the spindle l4 and with the same speed, a ply yarn is obtained on the takup bobbin 17 which is symmetrical and not subjected to any distortion since the two threads twine one upon the other in opposite directions. In this case it is no more necessary to subject the ply yarn obtained on the bobbin 17 to a further'thermal fixation treatment the ply yarn being no more affected by any defect due to distortion.

It is anyhow impossible using this type of high efficiency uptwister to obtain the same fancy ply yarn that can be obtained by means of the twister shown in FIG.

1, and the reason for this is that it has never been thought of or it has been found extremely difficult to vary the speed of one of the two threads 15 and 18 to obtain the knots or knops which characterize the fancy ply yarn and to vary at will the pitch of the helix which forms each spiral of the ply yarn.

This difficulty can be eliminated according to the present invention by 'means of the device illustrated in -FIG. 3.

A mechanism is inserted along the passage of one of the two threads 15 and 18 and specifically, in the illustrated case, along the passage of the thread 15 coming from the lower spindle 13, which mechanism allows to draw off the thread itself at variable speed. Said mechanism consists of three little pulleys 19,20, 21 the first two of which pulleys face each other and are stationary, while the third pulley 21 lies in between and can move back and forth alternately parallel to the arrows 22,23 along the path A-B.

ln this way the thread 15 is drawn off at variable speed, so that the thread 18 which twines around it due to the rotation of the spindle 14, takes the shape of a variable pitch helix as is shown in FIG. 5.

In fact when the pulley 21 approaches the other two, 19 and 20, in the direction of the arrow 23, the thread 15 remains almost stationary for some time and the thread 18 twines around it, thus forming a knop indicated in FIG. 5 by the numeral 18'; when pulley 21 moves away from pulleys l9 and 20 the thread 18 takes the shape of a helix 18" having a much larger pitch. The kinematics of said mechanism is illustrated in FIG. 4. Indicating by V the take-up speed for the ply yarn around the bobbin 17, by V, the alternate speed at which the pulley 21 moves (instantaneous speed) and by V, the speed at which the thread is drawn in, we have the following relationship:

V, V12 V,

By varying the instantaneous speed at which the pulley 21 moves and by varying the amplitude AB of the motion made by the same pulley it is possible to change the shape of the fancy ply yarn, as it is, for example, illustrated in FIGS. 6a, 6b and 6c.

In FIG. 7 a further improvement is shown: the thread 15 which constitutes the core of the ply yarn is unwound from the lower bobbin 28 which is stationary and around it are twisted in opposite directions the threads 18 and 18' respectively, the first coming from the spindle 13 which revolves in one direction and the second coming from the spindle 14 which revolves in the opposite direction but at the same speed.

In this way the fancy ply yarn illustrated in FIG. 8d is obtained which presents the considerable advantage, besides the formation of knops 18 similar to the ones that can be obtained by the ring twister, that the two threads 18",18 are helically twined in opposite directions thus avoiding also in this case the phenomenon of distortion and therefore the need of subjecting the tapered take-up bobbin 17 to a successive thermal fixation treatment.

Of course the device formed by the three pulleys 19, 20, 21 as illustrated in FIG. 7 can also be inserted between the bobbins 13 and 14 thus obtaining other fancy effects for the ply yarn, as illustrated in FIG. 8e.

It is also possible to insert notjust one of said devices 19,20, 21 but two or more of them to obtain even more complex fancy ply yarns, without departing from the scope of this invention.

The removal of the defect of distortion from the fancy ply yarn obtained according to this invention is not the only advantage characteristic of this invention. Another important advantage is obtained with respect to the ply yarn produced with ring twisters, such advantage consisting in a production rate which is 4 or 5 times greater.

This is due to the fact that using the device according to the present invention there is no need to brake and release considerable inertial masses only the thread being subjected to accelerations, whereas in the ring twister the braking, the arrest and the starting of the thread 2 (FIG. 1) 1) requires the braking, the arrest, and the starting of important masses such as the ones indicated by the devices 3,4 which are connected to gears and other mechanisms of considerable weight.

It is apparent from the above description that the process and the device according to the present invention represent a remarkable improvement for the production of fancy ply yarns.

What is claimed is:

1. A process for producing fancy yarn, comprising twisting a core yarn in one direction, winding an effect yarn about the core yarn in the opposite direction, and varying the speed of travel of the core yarn thereby to vary the spacing of the turns of effect yarn on the core yarn, the direction of twist of the core yarn and the direction of winding of the effect yarn remaining constant.

2. A process as claimed in claim 1, and winding a second effect yarn about said core yarn in a direction opposite to the direction of the first-mentioned effect yarn.

3. Apparatus for producing fancy yarn, comprising means to supply a core yarn, means to twist said core yarn continuously in one direction, means to wind about said core yarn an effect yarn continuously in the opposite direction, and means to vary the speed of travel of the core yarn relative to the winding means for the effect yarn thereby to impart variable spacing to the turns of effect yarn about the core yarn.

4. Apparatus as claimed in claim 3, and means to wind a second effect yarn about said core yarn continuously in the opposite direction from and after the firstmentioned effect yarn.

5. Apparatus as claimed in claim 4, and means to vary the speed of that portion of the core yarn which receives said second effect yarn relative to that portion of the core yarn that receives only the first-mentioned effect yarn thereby to impart to the core yarn three different velocities. 

2. A process as claimed in claim 1, and winding a second effect yarn about said core yarn in a direction opposite to the direction of the first-mentioned effect yarn.
 3. Apparatus for producing fancy yarn, comprising means to supply a core yarn, means to twist said core yarn continuously in one direction, means to wind about said core yarn an effect yarn continuously in the opposite direction, and means to vary the speed of travel of the core yarn relative to the winding means for the effect yarn thereby to impart variable spacing to the turns of effect yarn about the core yarn.
 4. Apparatus as claimed in claim 3, and means to wind a second effect yarn about said core yarn continuously in the opposite direction from and after the first-mentioned effect yarn.
 5. Apparatus as claimed in claim 4, and means to vary the speed of that portion of the core yarn which receives said second effect yarn relative to that portion of the core yarn that receives only the first-mentioned effect yarn thereby to impart to the core yarn three different velocities. 